filtering two arrays of objects

Question

I have to arrays of objects arr1 = [....] arr2 = [....]

now i'd like to find matching object based of it's id and then copy the values from one to another I made this using for loops:

for (let newCampaignState of data) {
            for (let oldCampaignState of this.campaigns) {
                if (oldCampaignState.id === newCampaignState.id) {
                    oldCampaignState.name = newCampaignState.name;
                }
            }
        }

how could i do this using more functional programming?

Answer 1

You can use filter fuction:

Code

 var arr1 = [{ name: 'category1', id: '1' }, { name: 'category3', id: '2' }, { name: 'category2', id: '2' }]; var arr2 = [{ name: 'category2', id: '5' }, { name: 'category2', id: '1' }, { name: 'category2', id: '2' }]; let filtered = []; arr1.filter(function(newData) { return arr2.filter(function(oldData) { if (newData.id === oldData.id && newData.name === oldData.name) { filtered.push({ 'id': newData.id, 'name': newData.name }) } }) }); document.body.innerHTML = ""; document.body.appendChild(document.createTextNode(JSON.stringify(filtered, null, 4))); 

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